Materials for thermobonding interlining include both woven and non-woven textile base materials. Woven materials proper are obtained by weaving or knitting threads, whereas non-woven materials are obtained by making up and then consolidating a web of threads or filaments.
To make a textile base material for interlining purposes, use has already been made of texturized synthetic threads, obtained either by the method of fixed false twisting or by the air jet texturizing technique.
In the particular technique of air jet texturizing, a first thread known as a "core" thread and a second thread known as an "effect" thread penetrate together into a texturizing nozzle with the effect thread being fed in faster than the core thread. The texturizing nozzle includes an internal chamber fed with a flow of compressed air suitable for establishing turbulence that tangles the filaments constituting the core thread and the effect thread in such a manner as to form loops of effect thread filaments which are inserted between and locked by the filaments of the core thread.
The use of that technique to produce a textile base material having good covering power, as can be obtained by a non-woven fabric, and good bulking, is already known from the Applicant's document EP 578 527.
Unfortunately, a difficulty appears when implementing thermobonding interlining in which the texturized threads form loops projecting from both faces. This difficulty appears during the various operations included in preparing thermobonding interlining pieces for making up the corresponding garments. These operations include in particular presenting the textile base material in the form of a stack or "lay-up" which consists in superposing a plurality of layers made up of the textile base material for thermobonding interlining, and then cutting the stack formed and compacted in this way so as to obtain a plurality of pieces for thermobonding interlining that are of determined shape. This plurality of pieces, while still in the form of a superposed and compacted stack, is forwarded to a subsequent manufacturing station where each thermobonding interlining piece is taken individually from said stack.
As a general rule, the initial laying up of a wide textile base material is achieved by forming successive superposed folds. This technique means that it is always the same faces that are face-to-face in successive folds. In other words, in any given fold, the face of the textile base material that includes the thermofusible polymer deposit is facing, and thus in contact with, the face of an adjacent fold that likewise includes thermofusible polymer deposit. The same applies to the opposite faces which similarly face one another and are in contact.
The Applicant has observed that when thermobonding interlining is performed with a textile base material made up of a woven fabric or of a weft knit, and including synthetic threads that have been texturized, in particular by jets of air, thereby forming loops that project from the top face having the spots of glue and also from the opposite bottom face, catching phenomena can occur, such that when individual thermobonding interlining pieces are taken from a stack that has been cut up, the catching phenomenon makes it difficult to take only one individual piece from the stack.